1. Field of the Invention
This invention relates to the establishment and maintenance of Fluid Sulfide Perfusion for therapeutic, scientific and medical purposes.
2. Description of Related Art
Sulfide is now known to play important roles in mammalian cell signaling. These include regulation of vascular smooth muscle tone, neuronal activity, liver bile production and general cell protection from the oxidative stress of aerobic metabolism. Because of the potential toxicity of hydrogen sulfide (H2S), its cellular/organismal concentration is tightly regulated by enzymatic production and consumption pathways so that toxic levels are not reached. However, too little sulfide, equivalent to too little reducing power and consequently too much oxidative stress, has been linked to cellular apotosis.
One way in which sulfide may achieve beneficial effects is by acting as a global cellular and organismal reductant, capable of shifting the cellular reductive/oxidative (redox) balance towards the reduced state and protecting against oxidative damage. Most cellular reductants are larger molecules compared to H2S and sulfide, and therefore cannot diffuse as rapidly, readily pass through cell membranes, or fit into smaller molecular spaces where some oxidized thiols occur. Therefore sulfide may be one of the most important cellular defenses against oxidative stress.
H2S and other sulfide compounds are regularly produced by human cellular metabolism. Sulfide levels can be augmented by the introduction of H2S rich gas, fluid or various sulfide supply compounds.
A variety of materials, both naturally occurring and artificially manufactured may be available for use as sulfide supply compounds. Sulfide supply compounds are chosen for their compatibility with each specific application. Diallyl Disulfide from Garlic or Lenthionine from Shitake mushrooms are derived from edible plants and are therefore likely to be safe. Flavor compounds presently used in food processing may also be used as sulfide supply compounds. Such compounds include but are not limited to Trithioacetone, 2-Thiophenethiol, and Dimethyl Trisulfide.
The short and long term repair and preservation of living biological material such as cultured cells, stem cells, bone, and whole organs is essential for the use of this material in research and clinical applications such as tissue growth and transplantation. Repair and preservation materials and methods are designed to limit oxidative damage and loss of viability. Although sulfide is produced endogenously, serving to protect cellular redox balance, compromised redox regulatory pathways in isolated cells or organs can be augmented by the exogenous addition of sulfide. A sulfide supply system designed to expose biological material to specific sulfide supply compounds, the ability to maintain concentration and rate of delivery during repair and preservation procedures could be used to enhance the viability of preserved samples, repair damaged tissue and enhance growth procedures.